ListView调整列的性能问题（分组）-ListViewResizeColumnsPerformanceIssues(Grouping)

11  

Your performance issue is due to not using IsVirtualizingWhenGrouping

您的性能问题是由于未使用IsVirtualizingWhenGrouping

You mentionned that using IsVirtualizingWhenGrouping was locking your application, and this is a known WPF issue (see : http://connect.microsoft.com/VisualStudio/feedback/details/780146/freeze-when-using-virtualizingpanel-isvirtualizingwhengrouping for more information on this bug happening when having a custom GroupStyle and IsVirtualizingWhenGrouping set to true)

您提到使用IsVirtualizingWhenGrouping锁定您的应用程序，这是一个已知的WPF问题（请参阅：http：//connect.microsoft.com/VisualStudio/feedback/details/780146/freeze-when-using-virtualizingpanel-isvirtualizingwhengrouping获取更多信息将自定义GroupStyle和IsVirtualizingWhenGrouping设置为true时发生此错误

Here is a quick workaroung to solve your issue : You just have to add an expander in the GroupStyle ControlTemplate. You'll then be able to use IsVirtualizingWhenGrouping and then have good performances when scrolling/Resizing columns.

以下是解决问题的快速工作方法：您只需在GroupStyle ControlTemplate中添加扩展器即可。然后，您可以使用IsVirtualizingWhenGrouping，然后在滚动/调整列时获得良好的性能。

Here is the code that works on my machine : (I put everything directly in MainWindow to simplify a bit)

这是在我的机器上运行的代码:(我将所有内容直接放在MainWindow中以简化一下）

EDIT: Here is a ControlTemplate that "hides" the expander. It's the original one from which I removed the unnecessary parts :

编辑：这是一个“隐藏”扩展器的ControlTemplate。这是我删除不必要部分的原始内容：

You can use it by setting it in the group style :

您可以通过在组样式中设置它来使用它：

2  

I think the problem is the ObservableCollection that is bound to your ListView and the case that you are adding 500 items per Add(). Each Add will raise 3 events. 2 NotifyPropertyChanged-Events for property Count and property Item[] and one the NotifyCollectionChanged-Event of the Collection, what counts up to 1500 events that are raised.

我认为问题是绑定到ListView的ObservableCollection以及每个Add（）添加500个项目的情况。每个Add都会引发3个事件。 2 NotifyPropertyChanged - 属性Count和属性Item []的事件以及Collection的NotifyCollectionChanged-Event，最多可计入1500个引发的事件。

I have exchanged the ObservableCollection with my own derived implementation of ObservableCollection that allows me to add a range of items and raise only 3 events once.

我已经使用我自己的ObservableCollection派生实现交换了ObservableCollection，它允许我添加一系列项目并且只引发一次3个事件。

    public class SmartCollection : ObservableCollection {
        public SmartCollection()
            : base() {

        }

        public SmartCollection(IEnumerable collection)
            : base(collection) {

        }

        public SmartCollection(List list)
            : base(list) {

        }

        public void AddRange(IEnumerable range) {
            foreach (var item in range) {
                Items.Add(item);
            }

            this.OnPropertyChanged(new PropertyChangedEventArgs("Count"));
            this.OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
            this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        }

        public void Reset(IEnumerable range) {
            if (range == null) {
                throw new ArgumentNullException("range", "range is null");
            }

            var rangeToAdd = range.ToList();
            this.Items.Clear();

            AddRange(rangeToAdd);
        }
    }

Using my Collection i changed your method to add the elements to the collection

使用我的Collection我改变了你的方法，将元素添加到集合中

private SmartCollection eventCollection = new SmartCollection();

private void dispatcherTimer_Tick(object sender, EventArgs e) {
  List newEvents = new List(500);

  for(var i = 0; i <500; i++){
    newEvents.Add(new Event {
      Name = string.Format("Name_{0}", eventCollection.Count + i),
      Date = DateTime.Now.ToString("MM.dd.yy HH:mm"),
      SecOnds= Convert.ToInt32(DateTime.Now.ToString("ss")),
      Desc = "Description"
    });
  }

  eventCollection.AddRange(newEvents);
}

0  

I'm not sure if this answer will suit, but I did get that performance back after setting the VirtualizingPanel.ScrollUnit property to "Item". The problem is, I had a number of visual glitches, which included seeing the Grouping object overlaying the top row when scrolling row-by-row (mouse wheel or key up/down), and the blurring across the rows immediately after scrolling as the renderer kicked in clear up the text.

我不确定这个答案是否适合，但是在将VirtualizingPanel.ScrollUnit属性设置为“Item”之后我确实得到了这个性能。问题是，我有一些视觉故障，其中包括在逐行滚动（鼠标滚轮或键向上/向下）时看到分组对象覆盖顶行，并在滚动后立即在行之间模糊渲染器开始清理文本。

VirtualizingPanel.ScrollUnit="Item"

Edit: Also change the VirtualizationMode back to Standard, VirtualizingPanel.VirtualizatiOnMode="Standard", and the visual glitches almost dissapear. (Having been testing with 50,000 rows).

编辑：还将VirtualizationMode更改回Standard，VirtualizingPanel.VirtualizatiOnMode=“Standard”，并且视觉故障几乎消失。 （已经测试了50,000行）。